1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

# The freezing point of benzene decreases by 0.45oC when 0.2g of acetic acid is added to 20g of benzene. If acetic acid associates to form a dimer in benzene, percentage association of acetic acid in benzene will be :(Kf for benzene =5.12Kkgmol−1)

A
80.4%
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
74.6%
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
94.6%
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
64.6%
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

## The correct option is B 94.6%Molality m=1000g/kg×0.2g(60g/mol×20g)=0.1667mΔTf=iKfm0.45=i×5.12×0.1667The vant Hoff factor i=0.527The degree of association α=(1−i)(1−1/n)The degree of association α=(1−0.527)(1−1/2)=0.946Percent association =0.946×100=94.6Hence, the option (C) is the correct answer.

Suggest Corrections
0
Join BYJU'S Learning Program
Related Videos
Depression in Freezing Point
CHEMISTRY
Watch in App
Join BYJU'S Learning Program